Phonon-assisted stimulated emission in thin (<55 Å) AlGaAs-GaAs-AlGaAs single quantum wells

Abstract

Since the initial report of phonon-assisted stimulated emission in AlGaAs-GaAs quantum wells, several laboratories have performed similar experiments which have produced a wide range of experimental data and interpretations. We present photopumped laser data (77 K) from three different AlGaAs-GaAs-AlGaAs single quantum well heterostructures grown by molecular beam epitaxy. Closely spaced end-to-end laser modes are observed one phonon energy (≊36 meV) below the n=1′ electron to light hole confined-particle state which we attribute to phonon-assisted stimulated emission. Also, the data are inconsistent with impurity related luminescence or optical absorption losses which have been suggested as alternative explanations. These results are important because these are the thinnest quantum wells to exhibit phonon-assisted stimulated emission and the first independent observation and confirmation of this important phenomenon.